diff --git a/compiler/resolution/cullOverReferences.cpp b/compiler/resolution/cullOverReferences.cpp
index 4697fed0791b..b7e20ed84442 100644
--- a/compiler/resolution/cullOverReferences.cpp
+++ b/compiler/resolution/cullOverReferences.cpp
@@ -483,11 +483,14 @@ static void maybeIssueRefMaybeConstWarning(ArgSymbol* arg) {
     bool useFunctionForWarning = (isTaskIntent | isArgThis) && arg->getFunction();
     Symbol* warnSym =
       useFunctionForWarning ? (Symbol*)arg->getFunction() : (Symbol*)arg;
-    USR_WARN(warnSym,
-            "inferring a default intent to be 'ref' is deprecated "
-            "- please %s '%s'",
-            intentName,
-            argName);
+    USR_FATAL_CONT(warnSym,
+                   "%s is const by default, but code attempted to modify it.",
+                   argName);
+    USR_PRINT("If you intended to modify %s, %s '%s'.",
+              argName,
+              intentName,
+              argName);
+    USR_STOP();
   }
 }
 
diff --git a/test/arrays/errors/error-const-use-as-ref-1.chpl b/test/arrays/errors/error-const-use-as-ref-1.chpl
new file mode 100644
index 000000000000..a50e919e4c43
--- /dev/null
+++ b/test/arrays/errors/error-const-use-as-ref-1.chpl
@@ -0,0 +1,13 @@
+// without ref gets infered to be const ref
+proc bar(A) { // should fail without ref
+  A = 1;
+}
+
+proc main() {
+  var A: [1..10] int;
+  A = 1..10;
+  writeln("A, ", A);
+
+  bar(A);
+  writeln("A, ", A);
+}
diff --git a/test/arrays/errors/error-const-use-as-ref-1.good b/test/arrays/errors/error-const-use-as-ref-1.good
new file mode 100644
index 000000000000..bb2fbfa65114
--- /dev/null
+++ b/test/arrays/errors/error-const-use-as-ref-1.good
@@ -0,0 +1,2 @@
+error-const-use-as-ref-1.chpl:2: error: A is const by default, but code attempted to modify it.
+note: If you intended to modify A, use an explicit 'ref' intent for the argument 'A'.
diff --git a/test/arrays/errors/error-const-use-as-ref-2.chpl b/test/arrays/errors/error-const-use-as-ref-2.chpl
new file mode 100644
index 000000000000..c49bd1ffb611
--- /dev/null
+++ b/test/arrays/errors/error-const-use-as-ref-2.chpl
@@ -0,0 +1,13 @@
+// without ref on the var args
+proc foobar(args...) {
+  args[0] = 2;
+}
+
+proc main() {
+  var A: [1..10] int;
+  A = 1..10;
+  writeln("A, ", A);
+
+  foobar(A);
+  writeln("A, ", A);
+}
diff --git a/test/arrays/errors/error-const-use-as-ref-2.good b/test/arrays/errors/error-const-use-as-ref-2.good
new file mode 100644
index 000000000000..aac2584c0ca1
--- /dev/null
+++ b/test/arrays/errors/error-const-use-as-ref-2.good
@@ -0,0 +1,2 @@
+error-const-use-as-ref-2.chpl:2: error: args is const by default, but code attempted to modify it.
+note: If you intended to modify args, use an explicit 'ref' intent for the argument 'args'.
diff --git a/test/deprecated/ref-maybe-const-this-intent.good b/test/deprecated/ref-maybe-const-this-intent.good
deleted file mode 100644
index b68134ce320b..000000000000
--- a/test/deprecated/ref-maybe-const-this-intent.good
+++ /dev/null
@@ -1,5 +0,0 @@
-ref-maybe-const-this-intent.chpl:28: warning: inferring a default intent to be 'ref' is deprecated - please add an explicit 'ref' task intent for 'this'
-ref-maybe-const-this-intent.chpl:19: warning: inferring a default intent to be 'ref' is deprecated - please add an explicit 'ref' task intent for 'this'
-ref-maybe-const-this-intent.chpl:4: warning: inferring a default intent to be 'ref' is deprecated - please use an explicit 'ref' this-intent for the method 'foo'
-(10, 12)
-(x = 2)
diff --git a/test/deprecated/ref-maybe-const-this-intent.numlocales b/test/deprecated/ref-maybe-const-this-intent.numlocales
deleted file mode 100644
index d00491fd7e5b..000000000000
--- a/test/deprecated/ref-maybe-const-this-intent.numlocales
+++ /dev/null
@@ -1 +0,0 @@
-1
diff --git a/test/deprecated/ref-maybe-const.chpl b/test/deprecated/ref-maybe-const.chpl
deleted file mode 100644
index 0780a0260865..000000000000
--- a/test/deprecated/ref-maybe-const.chpl
+++ /dev/null
@@ -1,29 +0,0 @@
-// infered to be const ref
-proc foo(A) {
-  return A;
-}
-
-// without ref gets infered to be const ref
-proc bar(A) { // should fail without ref
-  A = 1;
-}
-
-// without ref on the var args
-proc foobar(args...) {
-  args[0] = 2;
-}
-
-proc main() {
-  var A: [1..10] int;
-  A = 1..10;
-  writeln("A, ", A);
-
-  var B = foo(A);
-  writeln("B, ", B);
-
-  bar(A);
-  writeln("A, ", A);
-
-  foobar(A);
-  writeln("A, ", A);
-}
diff --git a/test/deprecated/ref-maybe-const.good b/test/deprecated/ref-maybe-const.good
deleted file mode 100644
index dcd2c0b49985..000000000000
--- a/test/deprecated/ref-maybe-const.good
+++ /dev/null
@@ -1,6 +0,0 @@
-ref-maybe-const.chpl:7: warning: inferring a default intent to be 'ref' is deprecated - please use an explicit 'ref' intent for the argument 'A'
-ref-maybe-const.chpl:12: warning: inferring a default intent to be 'ref' is deprecated - please use an explicit 'ref' intent for the argument 'args'
-A, 1 2 3 4 5 6 7 8 9 10
-B, 1 2 3 4 5 6 7 8 9 10
-A, 1 1 1 1 1 1 1 1 1 1
-A, 2 2 2 2 2 2 2 2 2 2
diff --git a/test/llvm/parallel_loop_access/different_numbers.chpl b/test/llvm/parallel_loop_access/different_numbers.chpl
index 719d02de20f5..da38fa7d55c1 100644
--- a/test/llvm/parallel_loop_access/different_numbers.chpl
+++ b/test/llvm/parallel_loop_access/different_numbers.chpl
@@ -8,7 +8,7 @@ proc start_loop3() { return 5; }
 proc end_loop3() { return 6; }
 
 //Check whether we generate different metadata number for loops
-proc loop (A, B, n) {
+proc loop (ref A, B, n) {
   //CHECK-LABEL: void @loop
   foreach i in 1..n {
     //CHECK-LABEL: start_loop1
diff --git a/test/llvm/parallel_loop_access/generation_inside_loop.chpl b/test/llvm/parallel_loop_access/generation_inside_loop.chpl
index 3cde1e1018e6..8d50a89cbb8b 100644
--- a/test/llvm/parallel_loop_access/generation_inside_loop.chpl
+++ b/test/llvm/parallel_loop_access/generation_inside_loop.chpl
@@ -11,7 +11,7 @@ proc end_block() { return 5; }
 // - basic block at start of loop
 // - basic block at the end of the loop
 
-proc loop (A, B, n) {
+proc loop (ref A, B, n) {
   //CHECK-LABEL: void @loop
   foreach i in 1..n {
     // CHECK-LABEL: start_block
diff --git a/test/llvm/parallel_loop_access/no_parallel_loop_accesses.chpl b/test/llvm/parallel_loop_access/no_parallel_loop_accesses.chpl
index 28f2164a89ba..6e0231dc9a21 100644
--- a/test/llvm/parallel_loop_access/no_parallel_loop_accesses.chpl
+++ b/test/llvm/parallel_loop_access/no_parallel_loop_accesses.chpl
@@ -12,7 +12,7 @@ proc keep(ref arg) { return 1; }
 proc mark() { return 2; }
 
 // CHECK: void @loop1
-proc loop1(A, B) {
+proc loop1(ref A, B) {
   // Check that we don't generate llvm.access.group metadata in
   // non-order-independent loops
   for i in 0..n {
diff --git a/test/llvm/parallel_loop_access/parallel_loop_accesses1.chpl b/test/llvm/parallel_loop_access/parallel_loop_accesses1.chpl
index 3cac0e3b9849..07cfaf41db66 100644
--- a/test/llvm/parallel_loop_access/parallel_loop_accesses1.chpl
+++ b/test/llvm/parallel_loop_access/parallel_loop_accesses1.chpl
@@ -2,7 +2,7 @@ config const n = 11;
 // check for correct access.group and llvm.loop.parallel_accesses hinting
 
 // CHECK: void @loop1
-proc loop1 (A, B) {
+proc loop1 (ref A, B) {
   foreach i in 0..n {
     // CHECK: load i32,
     // CHECK-SAME: !llvm.access.group ![[GROUP:[0-9]+]]
diff --git a/test/llvm/parallel_loop_access/parallel_loop_accesses2.chpl b/test/llvm/parallel_loop_access/parallel_loop_accesses2.chpl
index cb3fd190b132..2214afca86f1 100644
--- a/test/llvm/parallel_loop_access/parallel_loop_accesses2.chpl
+++ b/test/llvm/parallel_loop_access/parallel_loop_accesses2.chpl
@@ -2,7 +2,7 @@ config const n = 11;
 // check for correct access.group and llvm.loop.parallel_accesses hinting
 
 // CHECK: void @nestedLoops
-proc nestedLoops (A, B) {
+proc nestedLoops (ref A, B) {
   for i in 0..n {
     foreach j in 0..n {
       for k in 0..n {
diff --git a/test/llvm/parallel_loop_access/simple_forall.chpl b/test/llvm/parallel_loop_access/simple_forall.chpl
index 6ff579ecf2a8..5fa01c0e10be 100644
--- a/test/llvm/parallel_loop_access/simple_forall.chpl
+++ b/test/llvm/parallel_loop_access/simple_forall.chpl
@@ -5,7 +5,7 @@ proc main() {
   writeln(A[1], " ", A[n]);
 }
 
-proc loop(A) {
+proc loop(ref A) {
   forall i in 1..n {
     A[i] = 17.5 * i;
   }
diff --git a/test/llvm/parallel_loop_access/simple_loop.chpl b/test/llvm/parallel_loop_access/simple_loop.chpl
index f627d02cf0c3..830a3c46b9b4 100644
--- a/test/llvm/parallel_loop_access/simple_loop.chpl
+++ b/test/llvm/parallel_loop_access/simple_loop.chpl
@@ -1,5 +1,5 @@
 //Check whether we add parallel_loop_access metadata for loops at all
-proc loop (A, B, n) {
+proc loop (ref A, B, n) {
   foreach i in 1..n {
     // CHECK: !llvm.access.group ![[GROUP1:[0-9]+]]
     A[i] = 3*B[i];
diff --git a/test/llvm/parallel_loop_access/zippered_forall.chpl b/test/llvm/parallel_loop_access/zippered_forall.chpl
index d0669b72ee49..286819722be0 100644
--- a/test/llvm/parallel_loop_access/zippered_forall.chpl
+++ b/test/llvm/parallel_loop_access/zippered_forall.chpl
@@ -5,7 +5,7 @@ proc main() {
   writeln(A[1], " ", A[n]);
 }
 
-proc loop(A) {
+proc loop(ref A) {
   forall (i,j) in zip(1..n, 2..) {
     A[i] = 17.5 * j;
   }
diff --git a/test/llvm/vectorization/complicated_loop.chpl b/test/llvm/vectorization/complicated_loop.chpl
index d407a72a9939..a0d7406b8e53 100644
--- a/test/llvm/vectorization/complicated_loop.chpl
+++ b/test/llvm/vectorization/complicated_loop.chpl
@@ -1,5 +1,5 @@
 //This test checks whether vectorization occurs for more complicated loops
-proc loop (A, B, C) {
+proc loop (ref A, ref B, C) {
   // CHECK: <4 x i32>
   foreach j in 0..511 {
     var i = j : int(32);
diff --git a/test/llvm/vectorization/double_loop.chpl b/test/llvm/vectorization/double_loop.chpl
index bc1901553fe2..ad97be83ac21 100644
--- a/test/llvm/vectorization/double_loop.chpl
+++ b/test/llvm/vectorization/double_loop.chpl
@@ -1,5 +1,5 @@
 //Check whether vectorization occurs for nested loops
-proc loop (A, B) {
+proc loop (ref A, B) {
   foreach i in 0..511 {
     foreach j in 0..511 {
       // CHECK: <4 x i32>
diff --git a/test/llvm/vectorization/forall_loop.chpl b/test/llvm/vectorization/forall_loop.chpl
index 75e741ab4792..8be58060cf74 100644
--- a/test/llvm/vectorization/forall_loop.chpl
+++ b/test/llvm/vectorization/forall_loop.chpl
@@ -1,5 +1,5 @@
 //Check whether vectorization occurs for forall loop
-proc loop (A, B) {
+proc loop (ref A, B) {
   forall i in 0..511 {
       A[i] = B[i]*3;
   }
diff --git a/test/llvm/vectorization/nested_loop.chpl b/test/llvm/vectorization/nested_loop.chpl
index 6b1fa56bcf9c..4e523fae6a73 100644
--- a/test/llvm/vectorization/nested_loop.chpl
+++ b/test/llvm/vectorization/nested_loop.chpl
@@ -1,5 +1,5 @@
 
-proc loop (A, B, C, D, E, F, n) {
+proc loop (ref A, B, ref C, D, ref E, F, n) {
   foreach i in 1..n {
     A[i] = 3*B[i];
     foreach j in 1..n {
diff --git a/test/llvm/vectorization/simple_loop.chpl b/test/llvm/vectorization/simple_loop.chpl
index 6c09a3e29e2d..63248e174deb 100644
--- a/test/llvm/vectorization/simple_loop.chpl
+++ b/test/llvm/vectorization/simple_loop.chpl
@@ -1,7 +1,7 @@
 //Check whether vectorization occurs at all
 //This loop is trivial case for loop vectorizer and if
 //vectorization shouldn't happen it definitely won't happen in this case
-proc loop (A, B, n) {
+proc loop (ref A, B, n) {
   foreach i in 0..n {
     // CHECK: <4 x i32>
     A[i] = 3*B[i];
diff --git a/test/llvm/vectorization/zipped_loop.chpl b/test/llvm/vectorization/zipped_loop.chpl
index 8747c3f22884..1efb78510523 100644
--- a/test/llvm/vectorization/zipped_loop.chpl
+++ b/test/llvm/vectorization/zipped_loop.chpl
@@ -1,5 +1,5 @@
 //Check if zipped 'foreach' loop is vectorizable
-proc loop (A, B) {
+proc loop (ref A, B) {
   foreach (i,j) in zip(0..511, 0..511) {
     // CHECK: <4 x i32>
     A[i,j] = B[i,j]*3;
diff --git a/test/studies/isx/isx-no-return.chpl b/test/studies/isx/isx-no-return.chpl
index 32ce9842004d..8b1d5b8af65a 100644
--- a/test/studies/isx/isx-no-return.chpl
+++ b/test/studies/isx/isx-no-return.chpl
@@ -246,7 +246,7 @@ proc bucketSort(bucketID, trial: int, time = false, verify = false) {
 }
 
 
-proc bucketizeLocalKeys(myBucketedKeys, bucketID, myKeys, sendOffsets) {
+proc bucketizeLocalKeys(ref myBucketedKeys, bucketID, myKeys, sendOffsets) {
   var bucketOffsets: [LocBucketSpace] atomic int;
 
   bucketOffsets.write(sendOffsets);
@@ -262,7 +262,7 @@ proc bucketizeLocalKeys(myBucketedKeys, bucketID, myKeys, sendOffsets) {
 }
 
 
-proc countLocalBucketSizes(bucketSizes, myKeys) {
+proc countLocalBucketSizes(ref bucketSizes, myKeys) {
   forall key in myKeys {
     const bucketIndex = key / bucketWidth;
     bucketSizes[bucketIndex].add(1);
@@ -287,7 +287,7 @@ proc exchangeKeys(bucketID, sendOffsets, bucketSizes, myBucketedKeys) {
 }
 
 
-proc countLocalKeys(myLocalKeyCounts, bucketID, myBucketSize, myMinKeyVal) {
+proc countLocalKeys(ref myLocalKeyCounts, bucketID, myBucketSize, myMinKeyVal) {
   ref myBucket = allBucketKeys[bucketID];
   forall i in 0..#myBucketSize do
     myLocalKeyCounts[myBucket[i]].add(1);
@@ -330,7 +330,7 @@ proc verifyResults(bucketID, myBucketSize, myLocalKeyCounts) {
 }
 
 
-proc makeInput(myKeys, bucketID) {
+proc makeInput(ref myKeys, bucketID) {
   use Random;
   use Random.PCGRandomLib;
 
diff --git a/test/types/records/intents/error-const-use-as-ref-1.chpl b/test/types/records/intents/error-const-use-as-ref-1.chpl
new file mode 100644
index 000000000000..45a41986b8f6
--- /dev/null
+++ b/test/types/records/intents/error-const-use-as-ref-1.chpl
@@ -0,0 +1,13 @@
+record R {
+  var x: int = 11;
+  var y: int = 12;
+  proc foo() {
+    x = 10;
+  }
+  proc bar() { // should not warn
+    writeln((x,y));
+  }
+}
+var r = new R();
+r.foo();
+r.bar();
diff --git a/test/types/records/intents/error-const-use-as-ref-1.good b/test/types/records/intents/error-const-use-as-ref-1.good
new file mode 100644
index 000000000000..7a30e84ab6f3
--- /dev/null
+++ b/test/types/records/intents/error-const-use-as-ref-1.good
@@ -0,0 +1,2 @@
+error-const-use-as-ref-1.chpl:4: error: foo is const by default, but code attempted to modify it.
+note: If you intended to modify foo, use an explicit 'ref' this-intent for the method 'foo'.
diff --git a/test/types/records/intents/error-const-use-as-ref-2.chpl b/test/types/records/intents/error-const-use-as-ref-2.chpl
new file mode 100644
index 000000000000..0888d755966e
--- /dev/null
+++ b/test/types/records/intents/error-const-use-as-ref-2.chpl
@@ -0,0 +1,18 @@
+record R2 {
+  var x = 0;
+  proc ref foo() {
+    coforall l in Locales do on l {
+      editThis();
+    }
+  }
+  proc ref editThis() {
+    x += 1;
+  }
+
+  proc ref bar() {
+    begin on Locales[0] do editThis();
+  }
+}
+var r2 = new R2();
+r2.foo();
+writeln(r2);
diff --git a/test/types/records/intents/error-const-use-as-ref-2.good b/test/types/records/intents/error-const-use-as-ref-2.good
new file mode 100644
index 000000000000..dd4577b0a1a8
--- /dev/null
+++ b/test/types/records/intents/error-const-use-as-ref-2.good
@@ -0,0 +1,2 @@
+error-const-use-as-ref-2.chpl:4: error: this is const by default, but code attempted to modify it.
+note: If you intended to modify this, add an explicit 'ref' task intent for 'this'.
diff --git a/test/deprecated/ref-maybe-const-this-intent.chpl b/test/types/records/intents/error-const-use-as-ref-3.chpl
similarity index 58%
rename from test/deprecated/ref-maybe-const-this-intent.chpl
rename to test/types/records/intents/error-const-use-as-ref-3.chpl
index 5975db3b0d11..51540d8f3ac9 100644
--- a/test/deprecated/ref-maybe-const-this-intent.chpl
+++ b/test/types/records/intents/error-const-use-as-ref-3.chpl
@@ -1,18 +1,3 @@
-record R {
-  var x: int = 11;
-  var y: int = 12;
-  proc foo() {
-    x = 10;
-  }
-  proc bar() { // should not warn
-    writeln((x,y));
-  }
-}
-var r = new R();
-r.foo();
-r.bar();
-
-
 record R2 {
   var x = 0;
   proc ref foo() {
@@ -29,6 +14,5 @@ record R2 {
   }
 }
 var r2 = new R2();
-r2.foo();
 sync r2.bar();
 writeln(r2);
diff --git a/test/types/records/intents/error-const-use-as-ref-3.good b/test/types/records/intents/error-const-use-as-ref-3.good
new file mode 100644
index 000000000000..3322bf243ab0
--- /dev/null
+++ b/test/types/records/intents/error-const-use-as-ref-3.good
@@ -0,0 +1,2 @@
+error-const-use-as-ref-3.chpl:13: error: this is const by default, but code attempted to modify it.
+note: If you intended to modify this, add an explicit 'ref' task intent for 'this'.