diff --git a/gcc/testsuite/g++.dg/cpp1y/digit-sep-paste.C b/gcc/testsuite/g++.dg/cpp1y/digit-sep-paste.C
new file mode 100644
index 00000000000..41fb967ef8d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/digit-sep-paste.C
@@ -0,0 +1,11 @@
+// Test token pasting with digit separators avoided for preprocessed output.
+// { dg-do compile { target c++14 } }
+// { dg-options "-save-temps" }
+
+#define ZERO 0
+
+int
+f ()
+{
+  return ZERO'0'0; /* { dg-error "expected" } */
+}
diff --git a/gcc/testsuite/gcc.dg/c2x-digit-separators-3.c b/gcc/testsuite/gcc.dg/c2x-digit-separators-3.c
new file mode 100644
index 00000000000..cddb88fa880
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-digit-separators-3.c
@@ -0,0 +1,12 @@
+/* Test C2x digit separators.  Test token pasting avoided for preprocessed
+   output.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x -save-temps" } */
+
+#define ZERO 0
+
+int
+f (void)
+{
+  return ZERO'0'0; /* { dg-error "expected" } */
+}
diff --git a/libcpp/lex.c b/libcpp/lex.c
index b7ce85a0331..36cd2e30630 100644
--- a/libcpp/lex.c
+++ b/libcpp/lex.c
@@ -3725,6 +3725,7 @@ cpp_avoid_paste (cpp_reader *pfile, const cpp_token *token1,
 				|| b == CPP_NAME
 				|| b == CPP_CHAR || b == CPP_STRING); /* L */
     case CPP_NUMBER:	return (b == CPP_NUMBER || b == CPP_NAME
+				|| b == CPP_CHAR
 				|| c == '.' || c == '+' || c == '-');
 				      /* UCNs */
     case CPP_OTHER:	return ((token1->val.str.text[0] == '\\'