diff --git a/Eigen/src/Core/util/Macros.h b/Eigen/src/Core/util/Macros.h
index bc444b6b9..fad9a016e 100644
--- a/Eigen/src/Core/util/Macros.h
+++ b/Eigen/src/Core/util/Macros.h
@@ -178,7 +178,7 @@ using Eigen::ei_cos;
 #define EIGEN_RESTRICT __restrict
 
 #ifndef EIGEN_STACK_ALLOCATION_LIMIT
-#define EIGEN_STACK_ALLOCATION_LIMIT 16000000
+#define EIGEN_STACK_ALLOCATION_LIMIT 1000000
 #endif
 
 #ifndef EIGEN_DEFAULT_IO_FORMAT
@@ -188,9 +188,14 @@ using Eigen::ei_cos;
 // just an empty macro !
 #define EIGEN_EMPTY
 
+// concatenate two tokens
 #define EIGEN_CAT2(a,b) a ## b
 #define EIGEN_CAT(a,b) EIGEN_CAT2(a,b)
 
+// convert a token to a string
+#define EIGEN_MAKESTRING2(a) #a
+#define EIGEN_MAKESTRING(a) EIGEN_MAKESTRING2(a)
+
 // format used in Eigen's documentation
 // needed to define it here as escaping characters in CMake add_definition's argument seems very problematic.
 #define EIGEN_DOCS_IO_FORMAT IOFormat(3, AlignCols, " ", "\n", "", "")