diff --git a/src/shogun/labels/BinaryLabelEncoder.h b/src/shogun/labels/BinaryLabelEncoder.h
index 5bcd57e..69ed63e 100644
--- a/src/shogun/labels/BinaryLabelEncoder.h
+++ b/src/shogun/labels/BinaryLabelEncoder.h
@@ -14,6 +14,7 @@
 #include <shogun/labels/LabelEncoder.h>
 #include <shogun/lib/SGVector.h>
 #include <unordered_set>
+#include <fmt/ranges.h>
 namespace shogun
 {
 	/** @brief Implements a reversible mapping from
diff --git a/src/shogun/labels/MulticlassLabelsEncoder.h b/src/shogun/labels/MulticlassLabelsEncoder.h
index 41e9855..04151e4 100644
--- a/src/shogun/labels/MulticlassLabelsEncoder.h
+++ b/src/shogun/labels/MulticlassLabelsEncoder.h
@@ -13,6 +13,7 @@
 #include <shogun/labels/LabelEncoder.h>
 #include <shogun/labels/MulticlassLabels.h>
 #include <shogun/lib/SGVector.h>
+#include <fmt/ranges.h>
 
 namespace shogun
 {