diff --git a/headers/libs/alm/ALMLayout.h b/headers/libs/alm/ALMLayout.h
index b16bc46dc5..480e2b2698 100644
--- a/headers/libs/alm/ALMLayout.h
+++ b/headers/libs/alm/ALMLayout.h
@@ -120,8 +120,8 @@ private:
 	friend class YTab;
 	friend class Area;
 
-			float				InsetForTab(XTab* tab);
-			float				InsetForTab(YTab* tab);
+			float				InsetForTab(XTab* tab) const;
+			float				InsetForTab(YTab* tab) const;
 
 			BLayoutItem*		_LayoutItemToAdd(BView* view);
 
diff --git a/src/libs/alm/ALMLayout.cpp b/src/libs/alm/ALMLayout.cpp
index abde2f2ae2..8976801ff7 100644
--- a/src/libs/alm/ALMLayout.cpp
+++ b/src/libs/alm/ALMLayout.cpp
@@ -851,7 +851,7 @@ BALMLayout::GetSpacing(float *_hSpacing, float *_vSpacing) const
 
 
 float
-BALMLayout::InsetForTab(XTab* tab)
+BALMLayout::InsetForTab(XTab* tab) const
 {
 	if (tab == fLeft.Get())
 		return fLeftInset;
@@ -862,7 +862,7 @@ BALMLayout::InsetForTab(XTab* tab)
 
 
 float
-BALMLayout::InsetForTab(YTab* tab)
+BALMLayout::InsetForTab(YTab* tab) const
 {
 	if (tab == fTop.Get())
 		return fTopInset;