diff --git a/patches/win32-dll-build.patch b/patches/win32-dll-build.patch
index f341c2ba..989cf989 100644
--- a/patches/win32-dll-build.patch
+++ b/patches/win32-dll-build.patch
@@ -1,12 +1,12 @@
-From c3236b6df9af74ec4c0c5aa9d5b1d95b43392a4a Mon Sep 17 00:00:00 2001
+From 3689f3e8291a4ad289ad8580a9afb227cbb8e7eb Mon Sep 17 00:00:00 2001
 From: Kartik Singh <kssingh@hrl.com>
 Date: Thu, 12 Dec 2024 11:40:25 -0800
 Subject: [PATCH] Patch libsbcl build for Windows
 
 ---
  make-shared-library.sh  | 2 +-
- src/runtime/GNUmakefile | 4 ++--
- 2 files changed, 3 insertions(+), 3 deletions(-)
+ src/runtime/GNUmakefile | 8 ++++++--
+ 2 files changed, 7 insertions(+), 3 deletions(-)
 
 diff --git a/make-shared-library.sh b/make-shared-library.sh
 index 9acd9d843..39a951e9e 100755
@@ -19,16 +19,20 @@ index 9acd9d843..39a951e9e 100755
 -$GNUMAKE -C src/runtime libsbcl.so
 +$GNUMAKE -C src/runtime libsbcl.dll
 diff --git a/src/runtime/GNUmakefile b/src/runtime/GNUmakefile
-index 15e12a995..59d61592e 100644
+index 15e12a995..e02db7906 100644
 --- a/src/runtime/GNUmakefile
 +++ b/src/runtime/GNUmakefile
-@@ -132,8 +132,8 @@ libsbcl.a: $(OBJS)
+@@ -132,8 +132,12 @@ libsbcl.a: $(OBJS)
  	rm -f $@ ; ar rcs $@ $^
  
  PIC_OBJS = $(subst .o,.pic.o,$(OBJS))
 -libsbcl.so: $(PIC_OBJS)
 -	$(CC) -shared -o $@ $^ $(LIBS) $(SOFLAGS)
 +libsbcl.dll: $(PIC_OBJS)
++# The MINGW64 environment uses msvcrt.dll as the C runtime, which does
++# not export log1p and log2. We statically link MPFR, which provides
++# those two functions, into the DLL and then export the missing
++# functions via mswin64.def.
 +	$(CC) -shared -o $@ $^ $(LIBS) $(SOFLAGS) -Wl,-export-all-symbols -Wl,--whole-archive -lmpfr -Wl,--no-whole-archive mswin64.def
  # for this to work, you must have with-gcc-tls in your build features already.
  # can't define it here because then it conflicts if you have it in both places.