1 files changed, 4 insertions, 0 deletions
diff --git a/test/main.h b/test/main.h
index fcac0e3ab..3ccc2ae88 100644
--- a/test/main.h
+++ b/test/main.h
@@ -31,7 +31,11 @@
 // B0 is defined in POSIX header termios.h
 #define B0 FORBIDDEN_IDENTIFIER
 
+// Unit tests calling Eigen's blas library must preserve the default blocking size
+// to avoid troubles.
+#ifndef EIGEN_NO_DEBUG_SMALL_PRODUCT_BLOCKS
 #define EIGEN_DEBUG_SMALL_PRODUCT_BLOCKS
+#endif
 
 // shuts down ICC's remark #593: variable "XXX" was set but never used
 #define TEST_SET_BUT_UNUSED_VARIABLE(X) X = X + 0;