diff --git a/js/src/jit-test/tests/ion/bug1894456-1.js b/js/src/jit-test/tests/ion/bug1894456-1.js
new file mode 100644
index 000000000000..2b8f3e0afeb0
--- /dev/null
+++ b/js/src/jit-test/tests/ion/bug1894456-1.js
@@ -0,0 +1,6 @@
+var f32 = new Float32Array(1);
+for (var i = 0; i < 50; i++) {
+  if (f32[0] != null) {
+  }
+  try {} catch {}
+}
diff --git a/js/src/jit-test/tests/ion/bug1894456-2.js b/js/src/jit-test/tests/ion/bug1894456-2.js
new file mode 100644
index 000000000000..20b019738d62
--- /dev/null
+++ b/js/src/jit-test/tests/ion/bug1894456-2.js
@@ -0,0 +1,6 @@
+var f32 = new Float32Array(1);
+for (var i = 0; i < 50; i++) {
+  if (f32[0] != undefined) {
+  }
+  try {} catch {}
+}
diff --git a/js/src/jit/TypePolicy.cpp b/js/src/jit/TypePolicy.cpp
index 442bae54bad6..7d677bfb0605 100644
--- a/js/src/jit/TypePolicy.cpp
+++ b/js/src/jit/TypePolicy.cpp
@@ -229,7 +229,16 @@ bool ComparePolicy::adjustInputs(TempAllocator& alloc,
   switch (compare->compareType()) {
     case MCompare::Compare_Undefined:
     case MCompare::Compare_Null:
-      // Nothing to do for undefined and null, lowering handles all types.
+      MOZ_ASSERT(compare->rhs()->type() == MIRType::Undefined ||
+                 compare->rhs()->type() == MIRType::Null);
+      // IF the operand is float32, we must convert it to a double.
+      if (compare->lhs()->type() == MIRType::Float32) {
+        MInstruction* replace = MToDouble::New(alloc, compare->lhs());
+        def->block()->insertBefore(def, replace);
+        def->replaceOperand(0, replace);
+        return replace->typePolicy()->adjustInputs(alloc, replace);
+      }
+      // GVN and lowering handle all other types.
       return true;
     case MCompare::Compare_Int32:
       return convertOperand(0, MIRType::Int32) &&