diff --git a/Source/FreeImage/PluginEXR.cpp b/Source/FreeImage/PluginEXR.cpp
index faa8037..e88bd2d 100644
--- a/Source/FreeImage/PluginEXR.cpp
+++ b/Source/FreeImage/PluginEXR.cpp
@@ -28,16 +28,32 @@
 #pragma warning (disable : 4800) // ImfVersion.h - 'const int' : forcing value to bool 'true' or 'false' (performance warning)
 #endif 
 
-#include <ImfIO.h>
-#include <Iex.h>
-#include <ImfOutputFile.h>
-#include <ImfInputFile.h>
-#include <ImfRgbaFile.h>
-#include <ImfChannelList.h>
-#include <ImfRgba.h>
-#include <ImfArray.h>
-#include <ImfPreviewImage.h>
-#include <half.h>
+#include <OpenEXR/ImfIO.h>
+#include <OpenEXR/Iex.h>
+#include <OpenEXR/ImfOutputFile.h>
+#include <OpenEXR/ImfInputFile.h>
+#include <OpenEXR/ImfRgbaFile.h>
+#include <OpenEXR/ImfChannelList.h>
+#include <OpenEXR/ImfRgba.h>
+#include <OpenEXR/ImfArray.h>
+#include <OpenEXR/ImfPreviewImage.h>
+
+// The version can reliably be found in this header file from OpenEXR,
+// for both 2.x and 3.x:
+#include <OpenEXR/OpenEXRConfig.h>
+#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
+                                  (100*OPENEXR_VERSION_MINOR) + \
+                                  OPENEXR_VERSION_PATCH)
+
+// There's just no easy way to have an `#include` that works in both
+// cases, so we use the version to switch which set of include files we
+// use.
+#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
+#   include <Imath/half.h>
+#else
+    // OpenEXR 2.x, use the old locations
+#   include <OpenEXR/half.h>
+#endif
 
 
 // ==========================================================
@@ -66,11 +82,11 @@ public:
 		return ((unsigned)n != _io->read_proc(c, 1, n, _handle));
 	}
 
-	virtual Imath::Int64 tellg() {
+	virtual uint64_t tellg() {
 		return _io->tell_proc(_handle);
 	}
 
-	virtual void seekg(Imath::Int64 pos) {
+	virtual void seekg(uint64_t pos) {
 		_io->seek_proc(_handle, (unsigned)pos, SEEK_SET);
 	}
 
@@ -100,11 +116,11 @@ public:
 		}
 	}
 
-	virtual Imath::Int64 tellp() {
+	virtual uint64_t tellp() {
 		return _io->tell_proc(_handle);
 	}
 
-	virtual void seekp(Imath::Int64 pos) {
+	virtual void seekp(uint64_t pos) {
 		_io->seek_proc(_handle, (unsigned)pos, SEEK_SET);
 	}
 };
diff --git a/Source/FreeImage/PluginTIFF.cpp b/Source/FreeImage/PluginTIFF.cpp
index b9da767..96da4d7 100644
--- a/Source/FreeImage/PluginTIFF.cpp
+++ b/Source/FreeImage/PluginTIFF.cpp
@@ -39,7 +39,24 @@
 #include "Utilities.h"
 #include "tiffiop.h"
 #include "../Metadata/FreeImageTag.h"
-#include <half.h>
+// The version can reliably be found in this header file from OpenEXR,
+// for both 2.x and 3.x:
+#include <OpenEXR/OpenEXRConfig.h>
+#define COMBINED_OPENEXR_VERSION ((10000*OPENEXR_VERSION_MAJOR) + \
+                                  (100*OPENEXR_VERSION_MINOR) + \
+                                  OPENEXR_VERSION_PATCH)
+
+// There's just no easy way to have an `#include` that works in both
+// cases, so we use the version to switch which set of include files we
+// use.
+#if COMBINED_OPENEXR_VERSION >= 20599 /* 2.5.99: pre-3.0 */
+#   include <Imath/ImathVec.h>
+#   include <Imath/half.h>
+#else
+    // OpenEXR 2.x, use the old locations
+#   include <OpenEXR/ImathVec.h>
+#   include <OpenEXR/half.h>
+#endif
 
 #include "FreeImageIO.h"
 #include "PSDParser.h"
diff --git a/Makefile.fip b/Makefile.fip
index 60bedbc..193126d 100644
--- a/Makefile.fip
+++ b/Makefile.fip
@@ -28,7 +28,7 @@ LIBRARIES-$(USE_JPEG)   += -ljpeg
 LIBRARIES-$(USE_JPEG2K) += $(shell $(PKG_CONFIG) --libs libopenjp2)
 LIBRARIES-$(USE_MNG)    += -lmng
 LIBRARIES-$(USE_PNG)    += $(shell $(PKG_CONFIG) --libs libpng)
-LIBRARIES-$(USE_TIFF)   += $(shell $(PKG_CONFIG) --libs libtiff-4 IlmBase)
+LIBRARIES-$(USE_TIFF)   += $(shell $(PKG_CONFIG) --libs libtiff-4 Imath)
 LIBRARIES-$(USE_RAW)    += $(shell $(PKG_CONFIG) --libs libraw)
 LIBRARIES-$(USE_WEBP)    += $(shell $(PKG_CONFIG) --libs libwebp libwebpmux)
 
diff --git a/Makefile.gnu b/Makefile.gnu
index b11c554..3de5a1b 100644
--- a/Makefile.gnu
+++ b/Makefile.gnu
@@ -28,7 +28,7 @@ LIBRARIES-$(USE_JPEG)   += -ljpeg
 LIBRARIES-$(USE_JPEG2K) += $(shell $(PKG_CONFIG) --libs libopenjp2)
 LIBRARIES-$(USE_MNG)    += -lmng
 LIBRARIES-$(USE_PNG)    += $(shell $(PKG_CONFIG) --libs libpng)
-LIBRARIES-$(USE_TIFF)   += $(shell $(PKG_CONFIG) --libs libtiff-4 IlmBase)
+LIBRARIES-$(USE_TIFF)   += $(shell $(PKG_CONFIG) --libs libtiff-4 Imath)
 LIBRARIES-$(USE_RAW)    += $(shell $(PKG_CONFIG) --libs libraw)
 LIBRARIES-$(USE_WEBP)    += $(shell $(PKG_CONFIG) --libs libwebp libwebpmux)
 
diff --git a/Makefile.srcs b/Makefile.srcs
index 26e1a6d..d97eacf 100644
--- a/Makefile.srcs
+++ b/Makefile.srcs
@@ -180,7 +180,7 @@ INCLUDE-$(USE_JPEG)   += -DUSE_JPEG
 INCLUDE-$(USE_JPEG2K) += -DUSE_JPEG2K $(shell $(PKG_CONFIG) --cflags-only-I libopenjp2)
 INCLUDE-$(USE_MNG)    += -DUSE_MNG
 INCLUDE-$(USE_PNG)    += -DUSE_PNG    $(shell $(PKG_CONFIG) --cflags-only-I libpng)
-INCLUDE-$(USE_TIFF)   += -DUSE_TIFF   $(shell $(PKG_CONFIG) --cflags-only-I libtiff-4 IlmBase)
+INCLUDE-$(USE_TIFF)   += -DUSE_TIFF   $(shell $(PKG_CONFIG) --cflags-only-I libtiff-4 Imath)
 INCLUDE-$(USE_RAW)    += -DUSE_RAW    $(shell $(PKG_CONFIG) --cflags-only-I libraw)
 INCLUDE-$(USE_WEBP)   += -DUSE_WEBP   $(shell $(PKG_CONFIG) --cflags-only-I libwebp libwebpmux)
 INCLUDE = $(INCLUDE-yes)