diff --git a/config-unix.mk b/config-unix.mk
index 53d566af..aa60253d 100644
--- a/config-unix.mk
+++ b/config-unix.mk
@@ -74,8 +74,14 @@ endif
 
 # Need _GNU_SOURCE for strdup?
 RUNNER_CFLAGS=$(CFLAGS) -D_GNU_SOURCE
+RUNNER_LINKFLAGS=$(LINKFLAGS)
+
+ifeq (SunOS,$(uname_S))
+RUNNER_LINKFLAGS += -pthreads
+else
+RUNNER_LINKFLAGS += -pthread
+endif
 
-RUNNER_LINKFLAGS=$(LINKFLAGS) -pthreads
 RUNNER_LIBS=
 RUNNER_SRC=test/runner-unix.c