diff --git a/water/include/water/Dialect/Wave/IR/WaveAttrs.td b/water/include/water/Dialect/Wave/IR/WaveAttrs.td
index a459c94d2d..bcf18e0188 100644
--- a/water/include/water/Dialect/Wave/IR/WaveAttrs.td
+++ b/water/include/water/Dialect/Wave/IR/WaveAttrs.td
@@ -506,6 +506,7 @@ def WaveHyperparameterAttr : AttrDef<WaveDialect, "WaveHyperparameter"> {
 
   let parameters = (ins "::mlir::DictionaryAttr":$mapping);
   let assemblyFormat = "`<` $mapping `>`";
+  let genVerifyDecl = 1;
 
   let extraClassDeclaration = [{
     /// Get the concrete value for a symbol name, returns std::nullopt if not found
diff --git a/water/lib/Dialect/Wave/IR/WaveAttrs.cpp b/water/lib/Dialect/Wave/IR/WaveAttrs.cpp
index 6f08d6d78f..be11353aa4 100644
--- a/water/lib/Dialect/Wave/IR/WaveAttrs.cpp
+++ b/water/lib/Dialect/Wave/IR/WaveAttrs.cpp
@@ -483,6 +483,12 @@ WaveIndexMappingAttr WaveIndexMappingAttr::removeInput(Attribute input) const {
 // WaveHyperparameterAttr
 //===----------------------------------------------------------------------===//
 
+/// Returns true if `attr` is a signless i64 IntegerAttr.
+static bool isI64IntegerAttr(Attribute attr) {
+  auto intAttr = dyn_cast<IntegerAttr>(attr);
+  return intAttr && intAttr.getType().isSignlessInteger(64);
+}
+
 std::optional<int64_t>
 WaveHyperparameterAttr::getSymbolValue(StringRef symbolName) const {
   DictionaryAttr mapping = getMapping();
@@ -500,6 +506,18 @@ bool WaveHyperparameterAttr::hasSymbol(StringRef symbolName) const {
   return getMapping().get(symbolName) != nullptr;
 }
 
+LogicalResult
+WaveHyperparameterAttr::verify(function_ref<InFlightDiagnostic()> emitError,
+                               DictionaryAttr mapping) {
+  for (NamedAttribute attr : mapping) {
+    if (!isI64IntegerAttr(attr.getValue()))
+      return emitError() << "hyperparameter '" << attr.getName().getValue()
+                         << "' must be an i64 integer value, got "
+                         << attr.getValue();
+  }
+  return success();
+}
+
 //===----------------------------------------------------------------------===//
 // WaveSymbolAttr
 //===----------------------------------------------------------------------===//
@@ -718,11 +736,10 @@ LogicalResult HardwareConstraintAttr::verify(
   if (vectorShapes) {
     for (NamedAttribute attr : vectorShapes) {
       // TODO: verify that attr.getName() is a valid WaveSymbol
-      Attribute value = attr.getValue();
-
-      if (!isa<IntegerAttr>(value))
-        return emitError() << attr.getName()
-                           << " is not an IntegerAttr: " << attr.getValue();
+      if (!isI64IntegerAttr(attr.getValue()))
+        return emitError() << "vector_shapes entry '" << attr.getName().getValue()
+                           << "' must be an i64 integer value, got "
+                           << attr.getValue();
     }
   }
 
diff --git a/water/test/Dialect/Wave/attr-constraint-invalid.mlir b/water/test/Dialect/Wave/attr-constraint-invalid.mlir
index 127b0d9f4e..90fd5889d9 100644
--- a/water/test/Dialect/Wave/attr-constraint-invalid.mlir
+++ b/water/test/Dialect/Wave/attr-constraint-invalid.mlir
@@ -9,7 +9,7 @@ func.func private @test_num_dimensions_mismatch1() attributes { wave.constraints
 
 // -----
 
-// expected-error @below {{"M" is not an IntegerAttr: "BLOCK_M"}}
+// expected-error @below {{vector_shapes entry 'M' must be an i64 integer value, got "BLOCK_M"}}
 #hw_constraint = #wave.hardware_constraint<threads_per_wave = 64,
                                            waves_per_block = [1, 1, 1],
                                            mma_type = #wave.mma_kind<f32_16x16x16_f16>,
@@ -18,6 +18,14 @@ func.func private @test_num_dimensions_mismatch2() attributes { wave.constraints
 
 // -----
 
+// expected-error @below {{vector_shapes entry 'M' must be an i64 integer value, got 1 : i32}}
+#hw_constraint = #wave.hardware_constraint<threads_per_wave = 64,
+                                           waves_per_block = [1, 1, 1],
+                                           vector_shapes = {M = 1 : i32, N = 64}>
+func.func private @test_vector_shapes_non_i64() attributes { wave.constraints = [#hw_constraint] }
+
+// -----
+
 #hw_constraint = #wave.hardware_constraint<threads_per_wave = 64>
 #hw_constraint2 = #wave.hardware_constraint<threads_per_wave = 32>
 // expected-error @below {{only one hardware constraint is allowed}}
diff --git a/water/test/Dialect/Wave/ops-invalid.mlir b/water/test/Dialect/Wave/ops-invalid.mlir
index f661d4ffe4..20e3d8be7f 100644
--- a/water/test/Dialect/Wave/ops-invalid.mlir
+++ b/water/test/Dialect/Wave/ops-invalid.mlir
@@ -481,6 +481,11 @@ module attributes { wave.hyperparameters = #wave.hyperparameters<{}> } {
 
 // -----
 
+// expected-error @below {{hyperparameter 'A' must be an i64 integer value, got 42 : i32}}
+module attributes { wave.hyperparameters = #wave.hyperparameters<{A = 42 : i32}> } {}
+
+// -----
+
 module attributes { wave.hyperparameters = #wave.hyperparameters<{A = 42, C = 43}> } {
   // expected-error @below {{region #0 block #0 argument type #0 uses symbolic value #wave.symbol<"B"> not provided as a hyperparameter}}
   // expected-note @below {{available symbols: A, C}}