diff --git a/configure b/configure
index d551b38bd..89a1eb11e 100755
--- a/configure
+++ b/configure
@@ -655,7 +655,7 @@ process_toolchain() {
         enabled postproc || die "postproc_visualizer requires postproc to be enabled"
     fi
 
-    # Enable unit tests if we have a working C++ compiler
+    # Enable unit tests by default if we have a working C++ compiler.
     case "$toolchain" in
         *-vs*)
             soft_enable unit_tests
@@ -668,7 +668,7 @@ process_toolchain() {
             # x86 targets.
         ;;
         *)
-            check_cxx "$@" <<EOF && soft_enable unit_tests
+            enabled pthread_h && check_cxx "$@" <<EOF && soft_enable unit_tests
 int z;
 EOF
         ;;
diff --git a/libs.mk b/libs.mk
index 77ff2fc42..a6f1392dc 100644
--- a/libs.mk
+++ b/libs.mk
@@ -17,7 +17,6 @@ else
   ASM:=.asm
 endif
 
-
 #
 # Calculate platform- and compiler-specific offsets for hand coded assembly
 #
@@ -327,7 +326,11 @@ vpx.pc: config.mk libs.mk
 	$(qexec)echo 'Requires:' >> $@
 	$(qexec)echo 'Conflicts:' >> $@
 	$(qexec)echo 'Libs: -L$${libdir} -lvpx -lm' >> $@
+ifeq ($(HAVE_PTHREAD_H),yes)
 	$(qexec)echo 'Libs.private: -lm -lpthread' >> $@
+else
+	$(qexec)echo 'Libs.private: -lm' >> $@
+endif
 	$(qexec)echo 'Cflags: -I$${includedir}' >> $@
 INSTALL-LIBS-yes += $(LIBSUBDIR)/pkgconfig/vpx.pc
 INSTALL_MAPS += $(LIBSUBDIR)/pkgconfig/%.pc %.pc