diff --git a/var/spack/repos/builtin/packages/suite-sparse/graphblas_libm_dep.patch b/var/spack/repos/builtin/packages/suite-sparse/graphblas_libm_dep.patch
new file mode 100644
index 0000000000..441b0eff87
--- /dev/null
+++ b/var/spack/repos/builtin/packages/suite-sparse/graphblas_libm_dep.patch
@@ -0,0 +1,10 @@
+--- a/GraphBLAS/CMakeLists.txt
++++ b/GraphBLAS/CMakeLists.txt
+@@ -87,6 +87,7 @@
+     C_STANDARD_REQUIRED 11
+     PUBLIC_HEADER "Include/GraphBLAS.h" )
+ set_property ( TARGET graphblas PROPERTY C_STANDARD 11 )
++target_link_libraries ( graphblas m )
+
+ # create the static graphblas library.  Requires ANSI C11
+ add_library ( graphblas_static STATIC ${GRAPHBLAS_SOURCES} )
diff --git a/var/spack/repos/builtin/packages/suite-sparse/package.py b/var/spack/repos/builtin/packages/suite-sparse/package.py
index 7d89be0326..6b22e76f0e 100644
--- a/var/spack/repos/builtin/packages/suite-sparse/package.py
+++ b/var/spack/repos/builtin/packages/suite-sparse/package.py
@@ -60,6 +60,10 @@ class SuiteSparse(Package):
     # This patch removes unsupported flags for pgi compiler
     patch('pgi.patch', when='%pgi')
 
+    # This patch adds '-lm' when linking libgraphblas and when using clang.
+    # Fixes 'libgraphblas.so.2.0.1: undefined reference to `__fpclassify''
+    patch('graphblas_libm_dep.patch', when='@5.2.0:%clang')
+
     def install(self, spec, prefix):
         # The build system of SuiteSparse is quite old-fashioned.
         # It's basically a plain Makefile which include an header