diff --git a/graphblas/core/ss/matrix.py b/graphblas/core/ss/matrix.py
index 721e66e34..245c6c276 100644
--- a/graphblas/core/ss/matrix.py
+++ b/graphblas/core/ss/matrix.py
@@ -680,13 +680,18 @@ def iterkeys(self, seek=0):
         next_func = lib.GxB_Matrix_Iterator_next
         row_ptr = ffi_new("GrB_Index*")
         col_ptr = ffi_new("GrB_Index*")
-        while info == success:
-            key_func(it, row_ptr, col_ptr)
-            yield (row_ptr[0], col_ptr[0])
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Matrix iterator failed")
+        try:
+            while info == success:
+                key_func(it, row_ptr, col_ptr)
+                yield (row_ptr[0], col_ptr[0])
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Matrix iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def itervalues(self, seek=0):
         """Iterate over all the values of a Matrix.
@@ -710,12 +715,17 @@ def itervalues(self, seek=0):
         info = success = lib.GrB_SUCCESS
         val_func = getattr(lib, f"GxB_Iterator_get_{self._parent.dtype.name}")
         next_func = lib.GxB_Matrix_Iterator_next
-        while info == success:
-            yield val_func(it)
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Matrix iterator failed")
+        try:
+            while info == success:
+                yield val_func(it)
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Matrix iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def iteritems(self, seek=0):
         """Iterate over all the row, column, and value triples of a Matrix.
@@ -742,13 +752,18 @@ def iteritems(self, seek=0):
         next_func = lib.GxB_Matrix_Iterator_next
         row_ptr = ffi_new("GrB_Index*")
         col_ptr = ffi_new("GrB_Index*")
-        while info == success:
-            key_func(it, row_ptr, col_ptr)
-            yield (row_ptr[0], col_ptr[0], val_func(it))
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Matrix iterator failed")
+        try:
+            while info == success:
+                key_func(it, row_ptr, col_ptr)
+                yield (row_ptr[0], col_ptr[0], val_func(it))
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Matrix iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def export(self, format=None, *, sort=False, give_ownership=False, raw=False):
         """
diff --git a/graphblas/core/ss/vector.py b/graphblas/core/ss/vector.py
index c6162d782..79da58c97 100644
--- a/graphblas/core/ss/vector.py
+++ b/graphblas/core/ss/vector.py
@@ -376,12 +376,17 @@ def iterkeys(self, seek=0):
         info = success = lib.GrB_SUCCESS
         key_func = lib.GxB_Vector_Iterator_getIndex
         next_func = lib.GxB_Vector_Iterator_next
-        while info == success:
-            yield key_func(it)
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Vector iterator failed")
+        try:
+            while info == success:
+                yield key_func(it)
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Vector iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def itervalues(self, seek=0):
         """Iterate over all the values of a Vector.
@@ -405,12 +410,17 @@ def itervalues(self, seek=0):
         info = success = lib.GrB_SUCCESS
         val_func = getattr(lib, f"GxB_Iterator_get_{self._parent.dtype.name}")
         next_func = lib.GxB_Vector_Iterator_next
-        while info == success:
-            yield val_func(it)
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Vector iterator failed")
+        try:
+            while info == success:
+                yield val_func(it)
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Vector iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def iteritems(self, seek=0):
         """Iterate over all the indices and values of a Vector.
@@ -435,12 +445,17 @@ def iteritems(self, seek=0):
         key_func = lib.GxB_Vector_Iterator_getIndex
         val_func = getattr(lib, f"GxB_Iterator_get_{self._parent.dtype.name}")
         next_func = lib.GxB_Vector_Iterator_next
-        while info == success:
-            yield (key_func(it), val_func(it))
-            info = next_func(it)
-        lib.GxB_Iterator_free(it_ptr)
-        if info != lib.GxB_EXHAUSTED:  # pragma: no cover
-            raise _error_code_lookup[info]("Vector iterator failed")
+        try:
+            while info == success:
+                yield (key_func(it), val_func(it))
+                info = next_func(it)
+        except GeneratorExit:
+            pass
+        else:
+            if info != lib.GxB_EXHAUSTED:  # pragma: no cover
+                raise _error_code_lookup[info]("Vector iterator failed")
+        finally:
+            lib.GxB_Iterator_free(it_ptr)
 
     def export(self, format=None, *, sort=False, give_ownership=False, raw=False):
         """
diff --git a/graphblas/tests/test_matrix.py b/graphblas/tests/test_matrix.py
index 940658ebc..da9cbdfc5 100644
--- a/graphblas/tests/test_matrix.py
+++ b/graphblas/tests/test_matrix.py
@@ -3415,6 +3415,9 @@ def test_iteration(A):
     assert len(list(A.ss.iterkeys(N + 2))) == 0
     assert len(list(A.ss.iterkeys(-N))) == N
     assert len(list(A.ss.itervalues(-N - 1))) == N
+    assert next(A.ss.iterkeys()) in A
+    assert next(A.ss.itervalues()) is not None
+    assert next(A.ss.iteritems()) is not None
 
 
 def test_udt():
diff --git a/graphblas/tests/test_vector.py b/graphblas/tests/test_vector.py
index 8e010fe0b..a85347a05 100644
--- a/graphblas/tests/test_vector.py
+++ b/graphblas/tests/test_vector.py
@@ -2101,6 +2101,9 @@ def test_iteration(v):
     assert len(list(v.ss.iterkeys(2))) == 2
     assert len(list(v.ss.itervalues(N))) == 0
     assert len(list(v.ss.iteritems(N + 1))) == 0
+    assert next(v.ss.iterkeys()) in v
+    assert next(v.ss.itervalues()) is not None
+    assert next(v.ss.iteritems()) is not None
 
 
 def test_broadcasting(A, v):