diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 08a5b9ae2d7773f95fb7019ba13738ea6dc2bcbb..b64d9cfe90519da97ea058ce2afa8a21112eed0f 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,8 @@
+2017-03-29  Marek Polacek  <polacek@redhat.com>
+
+	PR c/79730
+	* c-decl.c (finish_decl): Check VAR_P.
+
 2017-03-27  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/80162
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index a0dc5bc0bee4fa7ced72033ef1c4d464061ca8c5..53c390c9e48d939330c555b12bddeea39235c14f 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -5066,7 +5066,7 @@ finish_decl (tree decl, location_t init_loc, tree init,
 	       when a tentative file-scope definition is seen.
 	       But at end of compilation, do output code for them.  */
 	    DECL_DEFER_OUTPUT (decl) = 1;
-	  if (asmspec && C_DECL_REGISTER (decl))
+	  if (asmspec && VAR_P (decl) && C_DECL_REGISTER (decl))
 	    DECL_HARD_REGISTER (decl) = 1;
 	  rest_of_decl_compilation (decl, true, 0);
 	}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index acbfee9929b85aa4058815460d9658257d77898b..d8e6f875c42e6c45173b8718e69fbab549bb2339 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-03-29  Marek Polacek  <polacek@redhat.com>
+
+	PR c/79730
+	* gcc.dg/pr79730.c: New test.
+
 2017-03-29  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libgfortran/78670
diff --git a/gcc/testsuite/gcc.dg/pr79730.c b/gcc/testsuite/gcc.dg/pr79730.c
new file mode 100644
index 0000000000000000000000000000000000000000..497823a486ce4e198f51e7b7c8e83b86a949a6ce
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr79730.c
@@ -0,0 +1,6 @@
+/* PR c/79730 */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu11" } */
+
+register int x() asm (""); /* { dg-error "invalid storage class" } */
+register float y() asm (""); /* { dg-error "invalid storage class" } */