diff --git a/package/libnspr/libnspr.mk b/package/libnspr/libnspr.mk
index 207da4ee67..8e58986b6c 100644
--- a/package/libnspr/libnspr.mk
+++ b/package/libnspr/libnspr.mk
@@ -21,6 +21,22 @@ LIBNSPR_CONF_ENV = \
 LIBNSPR_CONF_OPTS = --host=$(GNU_HOST_NAME)
 LIBNSPR_CONF_OPTS += --$(if $(BR2_ARCH_IS_64),en,dis)able-64bit
 
+# ./nspr/pr/include/md/_linux.h tests only __GLIBC__ version to detect
+# c-library features, list musl features here for now (taken from
+# Alpine Linux).
+ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
+LIBNSPR_CFLAGS += \
+	-D_PR_POLL_AVAILABLE \
+	-D_PR_HAVE_OFF64_T \
+	-D_PR_INET6 \
+	-D_PR_HAVE_INET_NTOP \
+	-D_PR_HAVE_GETHOSTBYNAME2 \
+	-D_PR_HAVE_GETADDRINFO \
+	-D_PR_INET6_PROBE
+endif
+
+LIBNSPR_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) $(LIBNSPR_CFLAGS)"
+
 ifeq ($(BR2_STATIC_LIBS),y)
 LIBNSPR_MAKE_OPTS = SHARED_LIBRARY=
 LIBNSPR_INSTALL_TARGET_OPTS = DESTDIR=$(TARGET_DIR) SHARED_LIBRARY= install