diff --git a/tests/Makefile.am b/tests/Makefile.am
index b1138602b..65978ae3f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -26,7 +26,7 @@ GPGSM = ../sm/gpgsm
 # if the shell used for inittests would uses an internal version of
 # pwd which handles symlinks differently.
 TESTS_ENVIRONMENT = GNUPGHOME=`/bin/pwd` GPG_AGENT_INFO= LC_ALL=C \
-                    GPGSM=$(GPGSM) $(srcdir)/runtest
+                    GPGSM="$(GPGSM)" "$(srcdir)/runtest"
 
 testscripts = sm-sign+verify sm-verify
 
diff --git a/tests/gpgme/Makefile.am b/tests/gpgme/Makefile.am
index f1c19eb16..60fb01df9 100644
--- a/tests/gpgme/Makefile.am
+++ b/tests/gpgme/Makefile.am
@@ -30,7 +30,7 @@ AM_CFLAGS =
 
 TESTS_ENVIRONMENT = LC_ALL=C \
 	EXEEXT=$(EXEEXT) \
-	PATH=../gpgscm:$(PATH) \
+	PATH="../gpgscm:$(PATH)" \
 	abs_top_srcdir=$(abs_top_srcdir) \
 	objdir=$(abs_top_builddir) \
 	GPGSCM_PATH=$(abs_top_srcdir)/tests/gpgscm
diff --git a/tests/gpgsm/Makefile.am b/tests/gpgsm/Makefile.am
index e54db7842..e784a3168 100644
--- a/tests/gpgsm/Makefile.am
+++ b/tests/gpgsm/Makefile.am
@@ -30,10 +30,10 @@ AM_CFLAGS =
 
 TESTS_ENVIRONMENT = LC_ALL=C \
 	EXEEXT=$(EXEEXT) \
-	PATH=../gpgscm:$(PATH) \
-	abs_top_srcdir=$(abs_top_srcdir) \
-	objdir=$(abs_top_builddir) \
-	GPGSCM_PATH=$(abs_top_srcdir)/tests/gpgscm
+	PATH="../gpgscm:$(PATH)" \
+	abs_top_srcdir="$(abs_top_srcdir)" \
+	objdir="$(abs_top_builddir)" \
+	GPGSCM_PATH="$(abs_top_srcdir)/tests/gpgscm"
 
 XTESTS = \
 	import.scm \
diff --git a/tests/migrations/Makefile.am b/tests/migrations/Makefile.am
index d90c9c7f9..6d2d2e8a6 100644
--- a/tests/migrations/Makefile.am
+++ b/tests/migrations/Makefile.am
@@ -30,10 +30,10 @@ AM_CFLAGS =
 
 TESTS_ENVIRONMENT = GPG_AGENT_INFO= LC_ALL=C \
 	EXEEXT=$(EXEEXT) \
-	PATH=../gpgscm:$(PATH) \
-	abs_top_srcdir=$(abs_top_srcdir) \
-	objdir=$(abs_top_builddir) \
-	GPGSCM_PATH=$(abs_top_srcdir)/tests/gpgscm
+	PATH="../gpgscm:$(PATH)" \
+	abs_top_srcdir="$(abs_top_srcdir)" \
+	objdir="$(abs_top_builddir)" \
+	GPGSCM_PATH="$(abs_top_srcdir)/tests/gpgscm"
 
 XTESTS = from-classic.scm \
 	extended-pkf.scm \
diff --git a/tests/openpgp/Makefile.am b/tests/openpgp/Makefile.am
index 8faf747fd..984b63f0a 100644
--- a/tests/openpgp/Makefile.am
+++ b/tests/openpgp/Makefile.am
@@ -35,10 +35,10 @@ fake_pinentry_SOURCES = fake-pinentry.c
 
 TESTS_ENVIRONMENT = LC_ALL=C \
 	EXEEXT=$(EXEEXT) \
-	PATH=../gpgscm:$(PATH) \
-	abs_top_srcdir=$(abs_top_srcdir) \
-	objdir=$(abs_top_builddir) \
-	GPGSCM_PATH=$(abs_top_srcdir)/tests/gpgscm
+	PATH="../gpgscm:$(PATH)" \
+	abs_top_srcdir="$(abs_top_srcdir)" \
+	objdir="$(abs_top_builddir)" \
+	GPGSCM_PATH="$(abs_top_srcdir)/tests/gpgscm"
 
 XTESTS = \
 	version.scm \