diff --git a/cpp/src/c_api/graph_mg.cpp b/cpp/src/c_api/graph_mg.cpp
index ed6cf4250f2..e634a1ba622 100644
--- a/cpp/src/c_api/graph_mg.cpp
+++ b/cpp/src/c_api/graph_mg.cpp
@@ -382,7 +382,7 @@ extern "C" cugraph_error_code_t cugraph_graph_create_mg(
       CAPI_EXPECTS(
       (properties->is_symmetric == TRUE),
       CUGRAPH_INVALID_INPUT,
-      "Invalid input arguments: The graph property must be symmetric if symmetrize is set to True.",
+      "Invalid input arguments: The graph property must be symmetric if 'symmetrize' is set to True.",
       *error);
     }
 
diff --git a/cpp/src/c_api/graph_sg.cpp b/cpp/src/c_api/graph_sg.cpp
index 63d7ae43c49..e7070234a10 100644
--- a/cpp/src/c_api/graph_sg.cpp
+++ b/cpp/src/c_api/graph_sg.cpp
@@ -585,7 +585,7 @@ extern "C" cugraph_error_code_t cugraph_graph_create_sg(
     CAPI_EXPECTS(
     (properties->is_symmetric == TRUE),
     CUGRAPH_INVALID_INPUT,
-    "Invalid input arguments: The graph property must be symmetric if symmetrize is set to True.",
+    "Invalid input arguments: The graph property must be symmetric if 'symmetrize' is set to True.",
     *error);
   }
 
@@ -761,7 +761,7 @@ cugraph_error_code_t cugraph_graph_create_sg_from_csr(
     CAPI_EXPECTS(
     (properties->is_symmetric == TRUE),
     CUGRAPH_INVALID_INPUT,
-    "Invalid input arguments: The graph property must be symmetric if symmetrize is set to True.",
+    "Invalid input arguments: The graph property must be symmetric if 'symmetrize' is set to True.",
     *error);
   }