diff --git a/tests/unit/libexpr-support/local.mk b/tests/unit/libexpr-support/local.mk
index 6b3ad64ee..ce0d9950c 100644
--- a/tests/unit/libexpr-support/local.mk
+++ b/tests/unit/libexpr-support/local.mk
@@ -16,4 +16,4 @@ libexpr-test-support_LIBS = \
     libstore-test-support libutil-test-support \
     libexpr libstore libutil
 
-libexpr-test-support_LDFLAGS := -lrapidcheck
+libexpr-test-support_LDFLAGS := -pthread -lrapidcheck
diff --git a/tests/unit/libstore-support/local.mk b/tests/unit/libstore-support/local.mk
index 2738278d8..59c3e09ca 100644
--- a/tests/unit/libstore-support/local.mk
+++ b/tests/unit/libstore-support/local.mk
@@ -14,4 +14,4 @@ libstore-test-support_LIBS = \
     libutil-test-support \
     libstore libutil
 
-libstore-test-support_LDFLAGS := -lrapidcheck
+libstore-test-support_LDFLAGS := -pthread -lrapidcheck
diff --git a/tests/unit/libutil-support/local.mk b/tests/unit/libutil-support/local.mk
index d085eda4e..b4c8f2475 100644
--- a/tests/unit/libutil-support/local.mk
+++ b/tests/unit/libutil-support/local.mk
@@ -12,4 +12,4 @@ libutil-test-support_CXXFLAGS += $(libutil-tests_EXTRA_INCLUDES)
 
 libutil-test-support_LIBS = libutil
 
-libutil-test-support_LDFLAGS := -lrapidcheck
+libutil-test-support_LDFLAGS := -pthread -lrapidcheck