diff --git a/easybuild/toolchains/compiler/gcc.py b/easybuild/toolchains/compiler/gcc.py
index 6a75a9e877..663b6385f6 100644
--- a/easybuild/toolchains/compiler/gcc.py
+++ b/easybuild/toolchains/compiler/gcc.py
@@ -94,6 +94,7 @@ class Gcc(Compiler):
         # no support for -march on POWER; implies -mtune=native
         (systemtools.POWER, systemtools.POWER): '-mcpu=native',
         (systemtools.POWER, systemtools.POWER_LE): '-mcpu=native',
+        (systemtools.RISCV64, systemtools.RISCV): '-march=' + systemtools.get_isa_riscv(),  # use all extensions
         (systemtools.X86_64, systemtools.AMD): '-march=native',  # implies -mtune=native
         (systemtools.X86_64, systemtools.INTEL): '-march=native',  # implies -mtune=native
     }
diff --git a/easybuild/tools/systemtools.py b/easybuild/tools/systemtools.py
index 3fefc1f95e..126bbb68c0 100644
--- a/easybuild/tools/systemtools.py
+++ b/easybuild/tools/systemtools.py
@@ -627,6 +627,30 @@ def get_cpu_features():
     return cpu_feat
 
 
+def get_isa_riscv():
+    """
+    Get supported ISA string
+    """
+    isa_string = 'rv64imafdc'
+    os_type = get_os_type()
+    if os_type == LINUX:
+        if is_readable(PROC_CPUINFO_FP):
+            _log.debug("Trying to determine ISA string on Linux via %s", PROC_CPUINFO_FP)
+            proc_cpuinfo = read_file(PROC_CPUINFO_FP)
+            isa_regex = re.compile(r"^isa\s*:\s*(.*)")
+            res = isa_regex.search(proc_cpuinfo)
+            if res:
+                isa_string = res.group(1)
+                _log.debug("Found ISA string using regex '%s': %s", isa_regex.pattern, isa_string)
+            else:
+                _log.debug("Failed to determine ISA string from %s", PROC_CPUINFO_FP)
+        else:
+            _log.debug("%s not found to determine ISA string", PROC_CPUINFO_FP)
+    else:
+        _log.debug("Could not determine ISA string (OS: %s), defaulting to: %s", os_type, isa_string)
+    return isa_string
+
+
 def get_gpu_info():
     """
     Get the GPU info
diff --git a/test/framework/systemtools.py b/test/framework/systemtools.py
index 73831b6bdb..36aec5a88b 100644
--- a/test/framework/systemtools.py
+++ b/test/framework/systemtools.py
@@ -52,6 +52,7 @@
 from easybuild.tools.systemtools import det_parallelism, det_pypkg_version, get_avail_core_count
 from easybuild.tools.systemtools import get_cuda_object_dump_raw, get_cuda_architectures, get_cpu_arch_name
 from easybuild.tools.systemtools import get_cpu_architecture, get_cpu_family, get_cpu_features, get_cpu_model
+from easybuild.tools.systemtools import get_isa_riscv
 from easybuild.tools.systemtools import get_cpu_speed, get_cpu_vendor, get_gcc_version, get_glibc_version, get_os_type
 from easybuild.tools.systemtools import get_os_name, get_os_version, get_platform_name, get_shared_lib_ext
 from easybuild.tools.systemtools import get_system_info, get_total_memory, get_linked_libs_raw
@@ -60,6 +61,31 @@
 
 PROC_CPUINFO_TXT = None
 
+PROC_CPUINFO_TXT_RISCV64 = """processor       : 0
+hart            : 2
+isa             : rv64imafdc
+mmu             : sv39
+uarch           : sifive,u74-mc
+
+processor       : 1
+hart            : 1
+isa             : rv64imafdc
+mmu             : sv39
+uarch           : sifive,u74-mc
+
+processor       : 2
+hart            : 3
+isa             : rv64imafdc
+mmu             : sv39
+uarch           : sifive,u74-mc
+
+processor       : 3
+hart            : 4
+isa             : rv64imafdc
+mmu             : sv39
+uarch           : sifive,u74-mc
+"""
+
 PROC_CPUINFO_TXT_RASPI2 = """processor : 0
 model name : ARMv7 Processor rev 5 (v7l)
 BogoMIPS : 57.60
@@ -720,6 +746,24 @@ def test_cpu_features_darwin(self):
                     'vme', 'vmx', 'x2apic', 'xd', 'xsave']
         self.assertEqual(get_cpu_features(), expected)
 
+    def test_isa_native(self):
+        """Test getting ISA string."""
+        isa_string = get_isa_riscv()
+        self.assertIsInstance(isa_string, str)
+
+    def test_isa_linux(self):
+        """Test getting ISA string (mocked for Linux)."""
+        st.get_os_type = lambda: st.LINUX
+        st.read_file = mocked_read_file
+        st.is_readable = lambda fp: mocked_is_readable(PROC_CPUINFO_FP, fp)
+
+        # tweak global constant used by mocked_read_file
+        global PROC_CPUINFO_TXT
+
+        PROC_CPUINFO_TXT = PROC_CPUINFO_TXT_RISCV64
+        expected = 'rv64imafdc'
+        self.assertEqual(get_isa_riscv(), expected)
+
     def test_cpu_architecture_native(self):
         """Test getting the CPU architecture."""
         arch = get_cpu_architecture()