diff --git a/src/Makefile.am b/src/Makefile.am
index 2343ab99ffd90a27e588344c1fae4f1491b4625e..569ccea6990c7939c166afb74eb9d9513cb324e1 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -55,7 +55,7 @@ AM_SOURCES = space.c runner.c queue.c task.c cell.c engine.c \
     runner_doiact_fft.c threadpool.c cooling.c
 
 # Include files for distribution, not installation.
-nobase_noinst_HEADERS = approx_math.h atomic.h cycle.h error.h inline.h kernel_hydro.h kernel_gravity.h \
+nobase_noinst_HEADERS = align.h approx_math.h atomic.h cycle.h error.h inline.h kernel_hydro.h kernel_gravity.h \
 		 kernel_long_gravity.h vector.h runner_doiact.h runner_doiact_grav.h runner_doiact_fft.h \
                  units.h intrinsics.h minmax.h kick.h timestep.h drift.h adiabatic_index.h io_properties.h \
 		 dimension.h equation_of_state.h \
diff --git a/src/align.h b/src/align.h
new file mode 100644
index 0000000000000000000000000000000000000000..84e2909c0866c18f0f8378df9d0efc8d0f6545b5
--- /dev/null
+++ b/src/align.h
@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Copyright (c) 2016 Matthieu Schaller (matthieu.schaller@durham.ac.uk).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+#ifndef SWIFT_ALIGN_H
+#define SWIFT_ALIGN_H
+
+/**
+ * @brief Defines alignment of structures
+ */
+#define SWIFT_STRUCT_ALIGN __attribute__((aligned(32)))
+
+#endif /* SWIFT_ALIGN_H */
diff --git a/src/cell.h b/src/cell.h
index 084fbcaef779d0083701c6c5a5aaba2c62f1768a..22ecaeb27fc2a958d9d33bb87bdf9422a3dea42f 100644
--- a/src/cell.h
+++ b/src/cell.h
@@ -30,6 +30,7 @@
 #include <stddef.h>
 
 /* Local includes. */
+#include "align.h"
 #include "lock.h"
 #include "multipole.h"
 #include "part.h"
@@ -74,7 +75,8 @@ struct pcell {
 
   /* Relative indices of the cell's progeny. */
   int progeny[8];
-};
+
+} SWIFT_STRUCT_ALIGN;
 
 /* Structure to store the data of a single cell. */
 struct cell {
@@ -208,7 +210,7 @@ struct cell {
 
 #endif
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /* Convert cell location to ID. */
 #define cell_getid(cdim, i, j, k) \
diff --git a/src/gravity/Default/gravity_part.h b/src/gravity/Default/gravity_part.h
index e85cf30d795a3373258e2e014f451e911d3a55a3..f06e65e5b30ebcd609c0c6204de33da17b770add 100644
--- a/src/gravity/Default/gravity_part.h
+++ b/src/gravity/Default/gravity_part.h
@@ -53,6 +53,6 @@ struct gpart {
      which this gpart is linked. */
   long long id_or_neg_offset;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 #endif /* SWIFT_DEFAULT_GRAVITY_PART_H */
diff --git a/src/hydro/Default/hydro_part.h b/src/hydro/Default/hydro_part.h
index 46c5d0e29ef0cbc21997ea02d12cd8e916d6c4c1..aa1d516e82995b3f389b7fea9f92687929bef63b 100644
--- a/src/hydro/Default/hydro_part.h
+++ b/src/hydro/Default/hydro_part.h
@@ -33,7 +33,7 @@ struct xpart {
   /* Old density. */
   float omega;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /* Data of a single particle. */
 struct part {
@@ -120,6 +120,6 @@ struct part {
   /* Pointer to corresponding gravity part. */
   struct gpart* gpart;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 #endif /* SWIFT_DEFAULT_HYDRO_PART_H */
diff --git a/src/hydro/Gadget2/hydro_part.h b/src/hydro/Gadget2/hydro_part.h
index 3fd5c28d22b4aa30bbb1a0f12571f079c297c0d7..94797b979af54f0ab8f41eacff49d392262d3249 100644
--- a/src/hydro/Gadget2/hydro_part.h
+++ b/src/hydro/Gadget2/hydro_part.h
@@ -28,7 +28,7 @@ struct xpart {
   /* Velocity at the last full step. */
   float v_full[3];
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /* Data of a single particle. */
 struct part {
@@ -110,6 +110,6 @@ struct part {
   /* Pointer to corresponding gravity part. */
   struct gpart* gpart;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 #endif /* SWIFT_GADGET2_HYDRO_PART_H */
diff --git a/src/hydro/Gizmo/hydro_part.h b/src/hydro/Gizmo/hydro_part.h
index c7983f9f94f321f330ad26645393728df6b2f04b..cc2e9c9db178c59189b6bad4ad81523725173147 100644
--- a/src/hydro/Gizmo/hydro_part.h
+++ b/src/hydro/Gizmo/hydro_part.h
@@ -26,7 +26,7 @@ struct xpart {
   /* Velocity at the last full step. */
   float v_full[3];
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /* Data of a single particle. */
 struct part {
@@ -196,4 +196,4 @@ struct part {
   /* Associated gravitas. */
   struct gpart *gpart;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
diff --git a/src/hydro/Minimal/hydro_part.h b/src/hydro/Minimal/hydro_part.h
index 2110730620853e9abb86717ff4df7febe7063a45..bf6c464777fe1abfe57b47a99229404d0f14ff86 100644
--- a/src/hydro/Minimal/hydro_part.h
+++ b/src/hydro/Minimal/hydro_part.h
@@ -47,7 +47,7 @@ struct xpart {
 
   float v_full[3]; /*!< Velocity at the last full step. */
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /**
  * @brief Particle fields for the SPH particles
@@ -120,6 +120,6 @@ struct part {
 
   struct gpart* gpart; /*!< Pointer to corresponding gravity part. */
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 #endif /* SWIFT_MINIMAL_HYDRO_PART_H */
diff --git a/src/part.h b/src/part.h
index 63996160e857ce3aae9ba4acce46a92e96c7e8fa..af39d10fafc11d4435ddbcc087fbf08178b18959 100644
--- a/src/part.h
+++ b/src/part.h
@@ -31,6 +31,7 @@
 #endif
 
 /* Local headers. */
+#include "align.h"
 #include "const.h"
 
 /* Some constants. */
diff --git a/src/task.h b/src/task.h
index f070451fe4e79e0c16dc3dcca1ce145c08841c47..4928dc00bcd7958efdd6987b5aec90ab4b3e92fa 100644
--- a/src/task.h
+++ b/src/task.h
@@ -26,6 +26,7 @@
 #include "../config.h"
 
 /* Includes. */
+#include "align.h"
 #include "cell.h"
 #include "cycle.h"
 
@@ -149,7 +150,7 @@ struct task {
   /*! Is this task implicit (i.e. does not do anything) ? */
   char implicit;
 
-} __attribute__((aligned(32)));
+} SWIFT_STRUCT_ALIGN;
 
 /* Function prototypes. */
 void task_unlock(struct task *t);