diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
index 553869a53f9..f929fddcf65 100644
--- a/src/glx/dri2_glx.c
+++ b/src/glx/dri2_glx.c
@@ -185,6 +185,13 @@ dri2_create_context(struct glx_screen *base,
    __DRIcontext *shared = NULL;
 
    if (shareList) {
+      /* If the shareList context is not a DRI2 context, we cannot possibly
+       * create a DRI2 context that shares it.
+       */
+      if (shareList->vtable->destroy != dri2_destroy_context) {
+	 return NULL;
+      }
+
       pcp_shared = (struct dri2_context *) shareList;
       shared = pcp_shared->driContext;
    }
diff --git a/src/glx/dri_glx.c b/src/glx/dri_glx.c
index 666423a7b15..9365224a696 100644
--- a/src/glx/dri_glx.c
+++ b/src/glx/dri_glx.c
@@ -587,6 +587,13 @@ dri_create_context(struct glx_screen *base,
       return NULL;
 
    if (shareList) {
+      /* If the shareList context is not a DRI context, we cannot possibly
+       * create a DRI context that shares it.
+       */
+      if (shareList->vtable->destroy != dri_destroy_context) {
+	 return NULL;
+      }
+
       pcp_shared = (struct dri_context *) shareList;
       shared = pcp_shared->driContext;
    }
diff --git a/src/glx/drisw_glx.c b/src/glx/drisw_glx.c
index f6aeda90abb..801ac7d470b 100644
--- a/src/glx/drisw_glx.c
+++ b/src/glx/drisw_glx.c
@@ -383,6 +383,13 @@ drisw_create_context(struct glx_screen *base,
       return NULL;
 
    if (shareList) {
+      /* If the shareList context is not a DRISW context, we cannot possibly
+       * create a DRISW context that shares it.
+       */
+      if (shareList->vtable->destroy != drisw_destroy_context) {
+	 return NULL;
+      }
+
       pcp_shared = (struct drisw_context *) shareList;
       shared = pcp_shared->driContext;
    }