Index: lib/Driver/Job.cpp
===================================================================
--- lib/Driver/Job.cpp
+++ lib/Driver/Job.cpp
@@ -99,7 +99,7 @@
 }
 
 void Command::printArg(raw_ostream &OS, StringRef Arg, bool Quote) {
-  const bool Escape = Arg.find_first_of("\"\\$") != StringRef::npos;
+  const bool Escape = Arg.find_first_of(" \"\\$") != StringRef::npos;
 
   if (!Quote && !Escape) {
     OS << Arg;
Index: test/Driver/verbose-output-quoting.c
===================================================================
--- test/Driver/verbose-output-quoting.c
+++ test/Driver/verbose-output-quoting.c
@@ -0,0 +1,9 @@
+// RUN: %clang --verbose -DSPACE="a b"  -c %s 2>&1 | FileCheck -check-prefix=SPACE     -strict-whitespace %s
+// RUN: %clang --verbose -DQUOTES=\"\"  -c %s 2>&1 | FileCheck -check-prefix=QUOTES    -strict-whitespace %s
+// RUN: %clang --verbose -DBACKSLASH=\\ -c %s 2>&1 | FileCheck -check-prefix=BACKSLASH -strict-whitespace %s
+// RUN: %clang --verbose -DDOLLAR=\$    -c %s 2>&1 | FileCheck -check-prefix=DOLLAR    -strict-whitespace %s
+
+// SPACE: -cc1 {{.*}} -D "SPACE=a b"
+// QUOTES: -cc1 {{.*}} -D "QUOTES=\"\""
+// BACKSLASH: -cc1 {{.*}} -D "BACKSLASH=\\"
+// DOLLAR: -cc1 {{.*}} -D "DOLLAR=\$"