diff --git a/overlays/bootstrap.nix b/overlays/bootstrap.nix
index e893ce3ed0..fd0d5651e6 100644
--- a/overlays/bootstrap.nix
+++ b/overlays/bootstrap.nix
@@ -162,7 +162,8 @@ in {
                 ++ final.lib.optional (versionAtLeast "8.6.5") ./patches/ghc/ghc-8.10-windows-add-dependent-file.patch
                 ++ fromUntil "8.10.1" "9.0"    ./patches/ghc/Cabal-unbreak-GHCJS.patch
                 ++ until              "8.10.5" ./patches/ghc/AC_PROG_CC_99.patch
-                ++ fromUntil "9.0.1"  "9.0.2" ./patches/ghc/AC_PROG_CC_99.patch
+                ++ fromUntil "9.0.1"  "9.0.2"  ./patches/ghc/AC_PROG_CC_99.patch
+                ++ fromUntil "8.10.5" "9.0.2"  ./patches/ghc/ghc-8.10.5-add-rts-exports.patch
                 ;
         in ({
             ghc844 = final.callPackage ../compiler/ghc {
diff --git a/overlays/patches/ghc/ghc-8.10.5-add-rts-exports.patch b/overlays/patches/ghc/ghc-8.10.5-add-rts-exports.patch
new file mode 100644
index 0000000000..eb7fe62cb2
--- /dev/null
+++ b/overlays/patches/ghc/ghc-8.10.5-add-rts-exports.patch
@@ -0,0 +1,26 @@
+diff --git a/rts/RtsSymbols.c b/rts/RtsSymbols.c
+index 9ca696c27c441059fb0fd82854e0737d5eccf2ad..d5b8cc5fece8395d277dd01cabdc309ac33406da 100644
+--- a/rts/RtsSymbols.c
++++ b/rts/RtsSymbols.c
+@@ -539,11 +539,21 @@
+ #define RTS_PROF_SYMBOLS /* empty */
+ #endif
+ 
++#if RTS_LINKER_USE_MMAP
++#define RTS_LINKER_USE_MMAP_SYMBOLS \
++      SymI_HasProto(allocateWrite)                                      \
++      SymI_HasProto(freeWrite)                                          \
++      SymI_HasProto(markExec)
++#else
++#define RTS_LINKER_USE_MMAP_SYMBOLS /* empty */
++#endif
++
+ #define RTS_SYMBOLS                                                     \
+       Maybe_Stable_Names                                                \
+       RTS_TICKY_SYMBOLS                                                 \
+       RTS_PROF_SYMBOLS                                                  \
+       RTS_LIBDW_SYMBOLS                                                 \
++      RTS_LINKER_USE_MMAP_SYMBOLS                                       \
+       SymI_HasProto(StgReturn)                                          \
+       SymI_HasProto(stg_gc_noregs)                                      \
+       SymI_HasProto(stg_ret_v_info)                                     \