diff --git a/GeographicLib-gcc11.patch b/GeographicLib-gcc11.patch
new file mode 100644
index 0000000..4ac12d4
--- /dev/null
+++ b/GeographicLib-gcc11.patch
@@ -0,0 +1,31 @@
+diff --git a/src/SphericalEngine.cpp b/src/SphericalEngine.cpp
+index 691d745..d46c6bd 100644
+--- a/src/SphericalEngine.cpp
++++ b/src/SphericalEngine.cpp
+@@ -409,22 +409,22 @@ namespace GeographicLib {
+                 SphericalEngine::coeff::Csize(N0, M )) * sizeof(double);
+     if (N == N0) {
+       Utility::readarray<double, real, false>(stream, C);
+-      if (skip) stream.seekg(std::ios::streamoff(skip), ios::cur);
++      if (skip) stream.seekg(std::streamoff(skip), ios::cur);
+       Utility::readarray<double, real, false>(stream, S);
+-      if (skip) stream.seekg(std::ios::streamoff(skip), ios::cur);
++      if (skip) stream.seekg(std::streamoff(skip), ios::cur);
+     } else {
+       for (int m = 0, k = 0; m <= M; ++m) {
+         Utility::readarray<double, real, false>(stream, &C[k], N + 1 - m);
+         stream.seekg((N0 - N) * sizeof(double), ios::cur);
+         k += N + 1 - m;
+       }
+-      if (skip) stream.seekg(std::ios::streamoff(skip), ios::cur);
++      if (skip) stream.seekg(std::streamoff(skip), ios::cur);
+       for (int m = 1, k = 0; m <= M; ++m) {
+         Utility::readarray<double, real, false>(stream, &S[k], N + 1 - m);
+         stream.seekg((N0 - N) * sizeof(double), ios::cur);
+         k += N + 1 - m;
+       }
+-      if (skip) stream.seekg(std::ios::streamoff(skip), ios::cur);
++      if (skip) stream.seekg(std::streamoff(skip), ios::cur);
+     }
+     return;
+   }