diff --git a/litedram/init.py b/litedram/init.py
index 94b68c4..df47844 100644
--- a/litedram/init.py
+++ b/litedram/init.py
@@ -956,10 +956,10 @@ def get_sdram_phy_c_header(phy_settings, timing_settings, geom_settings):
         assert phy_settings.memtype == "DDR4"
         r.define("SDRAM_PHY_CLAM_SHELL")
 
-    # litedram doesn't support multiple ranks
-    supported_memory = 2 ** (geom_settings.bankbits +
-                        geom_settings.rowbits +
-                        geom_settings.colbits) * phy_settings.databits // 8
+    # Define memory size.
+    supported_memory = 2**(geom_settings.bankbits +
+                           geom_settings.rowbits +
+                           geom_settings.colbits)*phy_settings.nranks*phy_settings.databits//8
     r.define("SDRAM_PHY_SUPPORTED_MEMORY", f"0x{supported_memory:016x}ULL")
 
     r.newline()